Implemented the initial Go framework

internal/builtin/output.go

@@ -0,0 +1,39 @@
+package builtin
+
+import (
+	"context"
+	"encoding/json"
+	"os"
+
+	"gitea.maximumdirect.net/eric/seriatim/internal/config"
+	"gitea.maximumdirect.net/eric/seriatim/internal/model"
+	"gitea.maximumdirect.net/eric/seriatim/internal/report"
+)
+
+type jsonOutputWriter struct{}
+
+func (jsonOutputWriter) Name() string {
+	return "json"
+}
+
+func (jsonOutputWriter) Write(ctx context.Context, out model.FinalTranscript, rpt report.Report, cfg config.Config) ([]report.Event, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	file, err := os.Create(cfg.OutputFile)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	enc := json.NewEncoder(file)
+	enc.SetIndent("", "  ")
+	if err := enc.Encode(out); err != nil {
+		return nil, err
+	}
+
+	return []report.Event{
+		report.Info("output", "json", "wrote placeholder transcript JSON"),
+	}, nil
+}